Biology of Reproduction, Vol 3, 218-222, Copyright © 1970 by Society for the Study of Reproduction

Androgen Regulation of Prostatic Membrane ATPase

¹ Biochemical Research Laboratories, Veterans Administration Hospital, and Department of Biochemistry, School of Medicine, State University of New York at Buffalo, Buffalo, New York 14214

The membrane ATPase of prostatic microsomes was further examined in order to better characterize its interaction with testosterone. Steroid treatment increased the rate of the cation-dependent ATPase at all concentrations of MgATP from 0.25-10 µM, maximum velocities of both treated and untreated enzyme occurring at 5 µM. The androgenized microsomes were more temperature sensitive also. A 10-degree rise in temperature (25-35 C) produced a significantly greater increase in the ATPase activity of the treated than of the control preparation. Tests of the two components of the ATPase process revealed that the androgen was ineffective upon the Na⁺-dependent phosphorylation of the enzyme but produced a significant acceleration of the K⁺-dependent dephosphorylation. Means to explain how the steroid regulates the catalytic and vectorial actions of the enzyme are discussed.